Yet another measurement of the current congressional polarization, and yet another reminder that nothing happens on the Hill without suspicion of political motive, arrived Wednesday on the op-ed page of the Akron Beacon Journal.

It was an 820-word essay from one of the four House members from that part of northeastern Ohio, Democratic Rep. Tim Ryan, headlined, “Why I changed my thinking on abortion.”

And, as is befitting one of the most divisive issues of the past half century, the two sides in the debate had diametrically different views of what they read.

The president of Planned Parenthood Action Fund, Cecile Richards, issued a statement hailing the lawmaker’s "honesty and courage in sharing how his views have evolved to support access to safe and legal abortion." The president of Ohio Right to Life, Michael Gonidakis, countered with a news release deriding Ryan for a "so-called conversion" and a "flip-flop" which should serve as "a wake-up call to voters in his current district as well as the rest of Ohio that he is nothing more than a political opportunist who will say anything to get elected."

For his part, the 41-year-old member of the Appropriations and Budget committees sought to explain how — after being reared to obey Roman Catholic doctrine and entering politics as a "pro-life" candidate — marriage and parenthood, plus two years as a state senator and a dozen years in Congress, have given him "a deeper understanding of the complexities and emotions that accompany the difficult decision that women and families make" when deliberating whether to end a pregnancy.

“While there are people of good conscience on both sides of this argument, one thing has become abundantly clear to me: The heavy hand of government must not make this decision,” he wrote. “I am not afraid to say that my position has evolved.”

The column is sure to be parsed, praised and ridiculed with extra frequency if Ryan runs for the Senate next year. He has said he will decide in the next month whether he will enter a potentially crowded Democratic primary, the winner of which would oppose Republican Sen. Rob Portman’s bid for a second term. The campaign will be run while Ohio reprises its quadrennial role as one of the most expensive and closely contested swing states in the presidential campaign.

Ryan, of course, made no mention of any statewide ambitions in his Beacon Journal piece, just as Portman said nothing about political calculations nearly two years ago. That was when he went on CNN to announce that his experience as a parent (he has a college-age son who is gay) had helped change his mind and he would support same-sex marriage , another of the defining social issues of our age.

Portman, 59, became the first Republican senator in that camp just as a consistent majority of Americans was starting to form in support for gay marriage. So, in terms of reflecting public opinion, Ryan was taking a much safer course this week. National polls for more than a decade have consistently showed solid majorities supporting the view that abortions should be legal in all or most cases. And Democratic base voters, crucial in primaries, overwhelmingly hold that view.

Where the congressman has stood on shakier ground, for years, has been with a voting record on abortion issues that rarely made either side content. Though he won his seat in 2002 as an unambiguous opponent of abortion rights, his freshman term voting record earned only a 72 percent support score from the National Right to Life Committee. In 2009, the group’s legislative director, Douglas Johnson, was labeling Ryan a "pro-life impersonator," and soon thereafter he was removed from the board of Democrats for Life of America — even though he voted that year in favor of adding abortion restrictions to the health care overhaul.

By the time of Ryan’s announcement his evolution appeared complete, advocacy groups on both sides of the issue agree. National Right to Life found nothing to like in his voting record during the past two years, while NARAL Pro-Choice America gave it a perfect score.

Relatively few votes on abortion-related bills and the intense advocacy on both sides in the debate, combined with the hollowing-out of the moderate ranks in both parties, has created more polarization than ever on the issue. When the House last week passed legislation codifying a ban on federal funding for almost all abortions, a solitary Republican voted "no" and just three Democrats voted "yes." (On that anti-abortion amendment to the health bill just five years ago, by contrast, 64 Democrats voted “yes” — all but 10 are gone now.)

The NARAL scorecard for the 113th Congress gave 93 percent of House members either zero or 100 percent, and the same was true for 97 percent on the National Right to Life scorecard, meaning just 11 members were viewed as somewhere in the center on abortion rights by both sides.

The situation was slightly less dramatic in the Senate, where eight members got middle-of-the-road scores from both groups — among them Minority Leader Harry Reid of Nevada, the only person currently in any congressional leadership post who’s not firmly in one camp or the other. (Senate Minority Whip Richard J. Durbin of Illinois transformed from an opponent to a supporter of abortion rights as a House member starting in the late 1980s, and the new vice chairman of the House Democratic Caucus, Joseph Crowley of New York, concluded a similar shift about a decade ago.)

The only lawmaker from either chamber who scored identical 50 percent ratings from both NARAL and Right to Life for 2013 and 2014 was Sen. Lisa Murkowski.

She has no known aspirations for higher office, and she won her second full term in 2010 as a write-in candidate in famously independent Alaska after her fellow Republicans denied her renomination. But, as Ohio’s Ryan has now underscored, trying to hold a somewhat subtle view in the middle on abortion rights is generally a lonely and politically dangerous pursuit.